Traffic signal

ABSTRACT

An additional light bulb arranged in each red or yellow lamp of a traffic light is energized through a radio-operated switch by an approaching emergency vehicle. The switch also interrupts the normal intermittent current supply to the red, yellow, and green lamps. Movement of the emergency vehicle is facilitated by the stopping of all traffic along its route not only in transverse directions, but also in the direction of movement of the vehicle and in the opposite direction.

United States Patent Harsanyl 51 Jan. 18, 1972 [541 TRAFFIC SIGNAL 2,074,246 3/1937 Adler, Jr ..340/46 2,881,409 4/1959 Cook et al. ...340/33 72 1 z E 1, 7. 1 or gfgg sg gi 4 5 3,257,641 6/1966 Campana et al .340/33 I22] Fl'lfld? 1969 Primary Examiner-Kathleen H. Clnfly [2| 1 App], No; 877,799 Assistant Examiner-Randall P. Myers Al!0rne v-- Kelman & Berman [30] Foreign Application Priority Data 57 ABSTRACT Nov. 26, 1968 Germany ..P l8 10 966.5 An additional light bulb arranged in each red or yellow lamp of a traffic light is energized through a radio-operated switch [52] U.S. Cl ..340/32 by an approaching emergency vehicle The Switch also imcp [511 3" "G083 l/ogg rupts the normal intermittent current supply to the red, yel- [58] FIeIdofSearch ..340/32,33,34,4 lowand greenlamps Movement ofthe emergency vehicle is facilitated by the stopping of all traffic along its route not only [56] References Cited in transverse directions, but also in the direction of movement UNITED STATES PATENTS 0f the vehicle and in the opposite direction.

1,981,577 1 H1934 Adler, Jr ..340/46 6 Claims, 3 Drawing Figures l l ,4 l7 v 9' TRAFFIC SIGNAL This invention relates to traffic controls, and particularly to the common type of visual signal in which red and green, or red, yellow and green lamps are cyclically energized.

This invention is more specifically concerned with a modification of the known traffic light which permits the normal cycle to be modified for giving preferential right of way to emergency vehicles, such as ambulances or fire fighting equipment. While emergency vehicles normally use sirens and flashing lights to assert their right of way, such audible and visible signals are not always effective, and emergency vehicles are involved in an unusually large number of collisions with other vehicles. Where traffic signals are manually operated by a police officer, he may block traffic transverse to the path of the emergency vehicle by means of a red light, and even more effective control is possible where traffic is controlled by the hand signals of a policeman. However, only an insignificant fraction of all urban intersections is controlled by manually operated traffic lights or by hand signals of policemen.

A primary object of the invention is the provision of a traffic light which secures the right of way for emergency vehicles even where the traffic light is automatically controlled, and does so more effectively than is currently possible with most hand-operated lights and with known radio-controlled lights.

According to this invention, a separately energized light source is arranged in the shell of each red or yellow lamp in the traffic light, thereby permitting all traffic at an intersection to be stopped simultaneously. When the traffic light is operated automatically in its usual cycle, a switch is provided to interrupt the cycle and to energize the warning light sources in the red or yellow lamps.

Other features, additional objects, and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understood by reference to the following description of preferred embodiments when considered in connection with the appended drawing in which:

FIG. 1 shows a traffic light of the invention in side elevational section, and partly by conventional symbols;

FIG. 2 diagrammatically illustrates another traffic signal of the invention; and

FIG. 3 is a block diagram of a radio receiver arrangement '4 which is common to the devices of FIGS. 1 and 2.

Referring now to the drawing in detail, and initially to FIG. 1, there is seen a housing 10 of four-side prismatic shape which serves as a support for three lamps 11, 12, 13 mounted in the housing one over another so as to face in the same direction. The lamps have shells 14, 15, 16 whose rear portions have an internal reflecting coating, and whose front portions consist of colored glass. Incandescent first light bulbs 17, 18, 19 in the three shells are supplied with electric current through respective individual current supply leads 22, 23, 24 and a common return lead 21. The structure described so far is conventional and operates in a known manner. When energized, the three lamps 11, 12, 13 respectively emit red, yellow, and green light.

A second or warning light bulb 42 is mounted in the shell 14 of the red lamp 11 and is supplied with electric current through leads 19', 20. A siren 41 mounted atop the housing 10 which supports all other illustrated elements is electrically operated in parallel circuit with the light bulb 42.

The leads 19, 20, when energized, draw current from a fuse box 26 connected with a 110 volt, 60 cycle line in a conventional manner. The leads 21, 22, 23, 24 are connected with the fuse box 26 through a motor-driven rotary switch 25, not shown in detail, which sequentially connects the three lamps 11, 12, 13 to the fuse box 26. Either the first power supply system of the leads 21-24 or the second power supply system of the leads 19', 20 is energized at any one time by a solenoidoperated switch assembly. Only the armature 34 of the solenoid is seen in FIG. 1 and carries the movable contacts of four normally closed switches 35, 36, 37, 38 respectively interposed between the leads 21-24 and the rotary switch 25, and of two normally open switches 39, 40 which normally separate the leads 19', 20 from the fuse box 26.

The solenoid coil is installed in a common housing 27 with components shown in more detail in FIG. 3 and including a radio receiver 28 having an external antenna 29 and tuned to a fixed frequency by a coil 30 and other conventional elements, not shown. The output signal of the receiver is fed to power amplifier 31 equipped with an adjustable input level control 43. A rectifier 32 is connected to the output terminals of the amplifier 32 and to a relay 33 in the energizing circuit of the aforementioned solenoid coil.

In the normal operation of the traffic light, the rotary switch 25 sequentially energizes the light bulbs 17, 18, 19 through the closed switches 35-39, and no current flows through the leads 19', 20. When an emergency vehicle equipped with a transmitter tuned to the frequency of the receiver 28 approaches the intersection at which the traffic light is installed, the armature 34 is shifted when the vehicle comes so close to the antenna 29 that the amplified and rectified output signal of the receiver 28 can trip the relay 33. Thereafter, the red lamp is illuminated by light from the bulb 42, and the siren 41 walls. Traffic is stopped until the emergency vehicle moves out of the effective range of the receiver 28. This range can be adjusted for specific conditions by means of the input level control 43 on the amplifier 31.

It will be appreciated that more than one traffic light of the type shown in FIG. 1 may need to be provided at an intersection, and that the several lights must be equipped with either a common rotary switch 25 or with proper synchronization for several rotary switches if employed.

A traffic light equipped with two sets of colored lamps 11, 12, 13, and 11', 12, 13 shown in FIG. 2, each lamp having a shell and a signal light source such as a light bulb in the manner of FIG. 1, but not explicitly shown in FIG. 2, and the red lamps 11, 11 being additionally equipped with light bulbs 42, 42' as sources of warning light. The two sets of signal light bulbs are energized by connected return leads 21, 21 and in pairs by leads 24, 22, 23 in such a manner that the red lamp of each set is lit simultaneously with the green lamp of the other set, and both yellow lamps are lit simultaneously, as is usual.

The two warning light bulbs 42,42 are arranged in parallel circuit with each other and with a siren 41 on current supply leads 19', 20. Either the power supply leads 21-24 or the power supply leads 19', 20 are energized by means of the switches 3540 on the solenoid armature 34 when a suitably tuned radio signal of adequate strength is sensed by the antenna 29 on a radio housing 27 equipped as described above with reference to FIGS. 1 and 3. The motorized rotary switch 25 and the fuse box 26 described above are also provided for the same purpose in the apparatus of FIG. 2.

While the traffic light illustrated in FIG. 2 has been shown to have two sets of lamps, it may also have four, each pair of sets being arranged in parallel and facing in opposite directions. When the armature 34 is attracted, all four red lamps are lit, and all traffic at the intersection comes to a halt. In the direction of travel of the emergency vehicle, only the right lane is occupied by other cars ahead of the intersection and only the left lane behind the intersection. By switching lanes in the intersection, the emergency vehicle can move freely through the intersection unless traffic is so heavy as to clog the roadway completely between successive lights. Under such conditions, traffic lights, of course, cannot clear a path for emergency use.

Whether warning lights 42, 42 are set in the red lamps, the yellow lamps, or both depends on local traffic laws. If vehicles are required to stop before entering the intersection if a facing light is yellow, it may be preferred to install the warning lights in the lamp shells having yellow glass fronts.

If so desired, controls more elaborate than those described above and shown in the drawing may be provided in an obvious manner to start the normal traffic light cycle in any desired stage after the emergency vehicle is out of effective range of the receiver 28, for example, at the stage at which all yellow lights are lit.

The apparatus shown in FIGS. 1 and 2 may be modified for manual operation by replacing the switch 25 and the switch assembly on the armature 34 by a single, manually operated selector switch having four positions respectively corresponding to the closing of the switches 35, 36, 37, and 19, the return leads 20, 21, 21 being permanently connected with the fuse box 26.

Other modifications and variations of the illustrated apparatus will readily suggest themselves to those skilled in the art, and it should be understood that the invention is not limited to the examples chosen herein for the purpose of the disclosure.

What is claimed is:

l. A traffic signal comprising, in combination:

a. a support;

b. a plurality of lamp means mounted on said support for emitting light signals of different respective colors in a common direction,

1. each lamp means including a shell and an electrically operated first light source in said shell,

2. one of said lamp means including an electrically operated second light source in said shell thereof;

0. first current supply means for supplying electric current to said first light sources in timed sequence;

d. second current supply means for supplying electric current to said second light source;

e. switch means for deenergizing said first supply means while energizing said second supply means, and for deenergizing said second supply means while energizing said first supply means; and I f. remotely controlled operating means for operating said switch means.

2. A signal as set forth in claim 1, wherein said one lamp means emits a red signal when a light source in the shell thereof is supplied with electric current.

3. A signal as set forth in claim 1, wherein said one lamp means emits a yellow signal when a light source in the shell thereof is supplied with electric current.

4. A signal as set forth in claim 1, further comprising an electrically operated source of an audible signal mounted on said support and connected to said second light source for joint supply of current thereto from said second supply means.

5. A signal as set forth in claim 1, wherein said operating means include radio receiver means adapted to produce an output signal, and an operating member connected to said switch means and responsive to said output signal for operating said switch means.

6. A signal as set forth in claim 5, further comprising control means for varying the effective range of said receiver. 

1. A traffic signal comprising, in combination: a. a support; b. a plurality of lamp means mounted on said support for emitting light signals of different respective colors in a common direction,
 1. each lamp means including a shell and an electrically operated first light source in said shell,
 2. one of said lamp means including an electrically operated second light source in said shell thereof; c. first current supply means for supplying electric current to said first light sources in timed sequence; d. second current supply means for supplying electric current to said second light source; e. switch means for deenergizing said first supply means while energizing said second supply means, and for deenergizing said second supply means while energizing said first supply means; and f. remotely controlled operating means for operating said switch means.
 2. one of said lamp means including an electrically operated second light source in said shell thereof; c. first current supply means for supplying electric current to said first light sources in timed sequence; d. second current supply means for supplying electric current to said second light source; e. switch means for deenergizing said first supply means while energizing said second supply means, and for deenergizing said second supply means while energizing said first supply means; and f. remotely controlled operating means for operating said switch means.
 2. A signal as set forth in claim 1, wherein said one lamp means emits a red signal when a light source in the shell thereof is supplied with electric current.
 3. A signal as set forth in claim 1, wherein said one lamp means emits a yellow signal when a light source in the shell thereof is supplied with electric current.
 4. A signal as set forth in claim 1, further comprising an electrically operated source of an audible signal mounted on said support and connected to said second light source for joint supply of current thereto from said second supply means.
 5. A signal as set forth in claim 1, wherein said operating means include radio receiver means adapted to produce an output signal, and an operating member connected to said switch means and responsive to said output signal for operatinG said switch means.
 6. A signal as set forth in claim 5, further comprising control means for varying the effective range of said receiver. 